Rocker arm for overhead valve gas engines



Dec. 17, 1935. w. M. SWARTZELL 2,024,401

ROCKER ARM FOR OVERHEAD VALVE GAS ENGINES Filed May 27, 1935 INVENTOR- Patented Dec. 17, 1935 FA'E'EN'E' @FFQE RGCKER ARM FUR @VERHEAD VALVE GAS ENGENES Wilbur M. Swartzell, Crestwood, N. Y., assignor of one-hair to Robert R. Page, Crestwood, N. Y.

Application May 27, 1933, Serial No. 673,168

14 Claims.

The present invention relates to an improvement in rocker arms for use in over head valve, or valve in the head gas engines.

One important feature is in the pivoted or hinged construction of the rocker arm, which has manifold advantages, first, to permit of rapid and accurate adjustment, without tools, second, to obviate noise of operation, third, to permit of easy removal of any rocker arm from its operative assembly on the rocker shaft and its ccnsequent easy replacement thereon, and fourth, to cause the wear of operation to be distributed over all of the bearing surfaces of the shaft and arm and its consequent longer life and continued quietness of operation, as there cannot be, under any condition of wear, any slack between the rocker arm bearing or shaft.

These, and other capabilities, will be apprehended as the herein description proceeds and it is obvious that modifications may be made in the structure herein without departing from the spirit hereof or the scope of the appended claims.

In the drawing,

Fig. 1 is a side view of a rocker arm in operative position on its rocker shaft, with the lift rod and valve stem shown dotted in their respective positions;

Fig. 2 is an end view of the rocker arm on a fragmented rocker shaft, the valve arm being sectioned on line 2-2, Fig. 1, looking in the direction of the arrows;

' Fig. 3 is a bottom view of the rocker arm of Fig. 1;

Fig. 4 is a side view of the rocker arm of Fig. i, with a portion broken away to illustrate added structural details;

Fig. 5 is a side view of an alternate form of rocker arm with a portion broken away to show added structural details;

Fig. 6 is a bottom View of the arm of Fig. 5; and

Fig. '7 is a fragmentary view showing a modified form of rocker arm connection.

In the present improvement the rocker arm is constructed of two coacting hinged members, i and 2, l, i being the cam or push rod end of the arm, with its component bearing hub sector it integral therewith, the other member, 2, having thereon the valve arm end 3, with its component bearing hub sector 5? integral therewith.

The hub sectors iiii'i are each provided with bored interconnecting hub hinge portions i[ii@- and M respectively, and these are pivotally joined in operative hinged connection by a pintle or pin i2, Figs. 1, 2, 3 and 4, being mounted in said hinge portions. The hub hinge lfi-lii-i I' and the pin 82, and the axis thereof are external to the axis of the rocker shaft 9. The semicylindrical hinge hubs are cut away at the top 5* portions, as at 43, Fig. 1, so as to allow of approach of the two ends thereof, as wear occurs. A slight clearance may also be provided between the lower ends of the hinge hub above the hinge point, for the same purpose. 0

Each hinge hub may be provided with a rocker-shaft bushing sector 88, which may be affixed in operative position in sectors iii-4T by rivets iii-54.

The cam push rod end i, of the rocker arm is 15 provided with a bored and threaded end i, Fig. i, in which is mounted a threaded ball ended adjusting stud 5, the ball end 5 of which engages with the cam push rod A in the usual well known manner. To permit of easy adjustment 2 of the adjusting stud 5 to take up clearance between the ball end 5 and the top end of push rod A, the upper end of the stud 5 is provided with a cross pin 6 which provides a finger wrench whereby to adjust stud 5.

To prevent stud 5 from vibratory rotation or loosening action during operation, a frictioning stud lock spring 18, substantially U shaped, is sprung between the neck of the ball ended stud 5' and the notch in a spring seating lug 20', 3 which is integral on the hub face it. The spring "5, as in Fig. 3, is provided with two curve contoured ends l9 and 2%, which respectively seat on the stud 5 and the seat on lug 29'.

This spring exerts sufiicient pressure against 35 stud 5' to prevent its independent movement under operative conditions but permits easy manual rotation by hand for resetting, when desired. I

In normal practice, when it is desired to re- 4 move the rocker arm from rock shaft 9, the valve stem 13 is pushed down a suflicient distance to permit valve arm 2, to be pushed down also, this action increases the space l3, Fig. 1 so that the cam rod arm may be upwardly unseated from its ball seat connection with cam arm A, and then the entire rocker arm assembly moved side-wise on shaft 9, opened fully on its hinge point 12, and removed completely from shaft 9. The steps of replacement of the rocker 50 a coiled expansion spring 22, seated in recessed bores 2i2l, so that should a slight wear occur which is not immediately adjusted, the outward pressure of the spring 22 would keep the cam and valve terminals, 5 and 3 respectively, in tensional contact with the cam and valve rod ends, and thus operate without slap.

Fig. 4, in which like indices indicate the same parts as in Fig. 1, also discloses another form of friction stud lock at the cam rod end, and this is shown as being a ball 34 located in a bored boss 35, with a threaded head screw 32 located in said bore, and a tension spring 33 between the inner end of screw 32 and the ball 34, thereby to thrust the ball 34 against the threads of stud 5', to hold the same in adjusted position.

In Fig.2, there is shown a further novel improvement made permissible by my present hinged rocker arm construction, and this is shown at E5, and comprises a cylindrical seat l5 cut into the shaft 9, so as to create an arm registry seat, one for each rocker arm so mounted. This arrangement positively locates each rocker arm on shaft 9 at its registry point with its cooperative cam and valve rod position, and thereby does away with all rocker arm spacers, springs and pins, and further simplifies the removal and replacement of the rocker arms, manually and without tools.

Figs. 5 and 6 disclose a modified form of hinged rocker arm assembly, in which similar parts to those shown in Figs. 1, 2, 3 and 4 bear like indices.

The hub sectors l6 and H, are each provided with a separate hinge pin 28--29 located in a separate bore in each sector, the hinge bores being spaced from each other and being parallel with the axis of shaft 9, the hinge forming bosses 39 3I being provided with four traversing blade receiving slots therein into each of which is located a hinge blade 21, the opposite ends of these blades being rounded, and bored to receive the traversing hinge pins 28-29, thus as described for the arm of Fig. 1, this latter structure acts in the same manner in operation and removal, but provides a stronger hinge connection.

The upper arm end of the rocker arms, I and 2, Fig. 5, is bored as at 23-23 and an expansion spring 24 traverses the clearance opening 53, and is seated in the blind bore 23 of arm 2. The other end of the expansion spring rests on the end of a sliding pin 25, in arm I, at the opposite end of which it thrusts a friction ball against the threads of stud 5, to lock the stud against undesired rotation, after adjustment. The spring 243 in this construction has the double function of preventing slap between the valve and cam rod ends and the rocker arm ends 3 and 5.

In use, the longitudinally split, hinged rocker arm hereinbefore set out, after being adjusted so that both the ball end 5 and the valve end 3 are in correctly adjusted operative positions, all valve operating action and forces'act upwardly in the direction of the arrows X, Fig. 1. This tends to cause the hinge sectors to close upon the rocker arm shaft, and as wear occurs on the shaft and bushing sectors 8-8, the wear is distributed over all of the contacting bushing and shaft surfaces, evenly.

Thus, instead of the bushings wearing at their bottom surfaces only as in a solid bushed rocker arm, thereby eventually creating unadjustable clearances between the upper part of the solid bushing and the shaft, with consequent noise, my present construction adjusts itself to any consequent wear, wears longer, and is completely noiseless because there is no play between any of the coacting parts or surfaces.

In Fig. 7 there is shown amodified form of connector between the' half hubs 6-41, and this comprises a flat spring steel blade '36 the opposite ends of which are caught in notches 38-39 formed under lugs 4Q H, and having two rivets 31-31 further locking the spring blade connector 36 to the sectors. In practice the sectors are folded about the shaft 9 thus curving the spring connection 36 to suit.

Further, due to the construction outlined, the arms are in slightly flexible relation to one another, so that the usual relative clearances between the valve and cam rod ends and the cooperative rocker arm contact faces may be considerably less than in a solid rocker arm construction, where care must be exercised, when setting the rocker arm clearances, cold, to be in proper contact after the engine heats up, in normal running.

What I claim is:

1. A rocker arm assembly arranged for oscillation on a rocker shaft and including a pair of opposed hub sectors each of less arcuate extent than said sectors being hingedly connected at one end of each sector and surrounding said shaft with their remaining ends spaced, spring means normally urging said last ends apart, and rocker arms each extending from a respective sector.

2. A rocker arm for a shaft, said rocker arm comprising a pair of opposed hub sections, each section adapted to extend about half Way around the shaft; one pair only of the adjacent ends of said sections being substantially hing edly connected; and lever arms secured to the respective sections; the hinge connection between said sections and the disposition of the sections and lever arms allowing movement of said sections and lever arms far enough from said shaft to permit complete lateral removal of the rocker arm entirely remote from the shaft.

3. A rocker arm as in claim 2, in which the hinge connection comprises a plurality of parallel links pivoted at opposite ends to the respective sections.

4. A rocker arm as in claim 2, in which the hinge connection comprises a spring secured to' the respective sections.

5. A rocker arm for a shaft, said rocker arm comprising a pair of opposed hub sections, each section extending about half way around the shaft; one pair only of the adjacent ends of said sections being substantially hingedly connected; and lever arms secured to the respective sections; the hinge connection between said sections comprising a flat spring urging the sections apart.

6. In combination, a shaft; a pair of opposed hub sections cooperating to form a bearing hub disposed substantially around said shaft; said sections being substantially hingedly connected; lever arms secured to the respective sections and extending outwardly approximately radially from the shaft; active and motive reciprocatory members pressing against said arms in a direction to force opposite portions of said sections toward each other and to the shaft; all of the inner curved faces of said sections adjacent to the shaft engaging the shaft; each pair of adjacent ends of both sections lying in a common plane substantially perpendicular to the shaft.

7. A rocker arm for a shaft, said rocker arm comprising a pair of opposed members each including an arm and a hub section, each section being adapted to extend about opposite parts of the shaft; one pair only of the adjacent ends of said sections being substantially hingedly connected; said lever arms being secured to the respective sections; adjusting means on one of the arms for engaging an actuating means and adjusting the distance of the arm from the actuating means; detent means engaging the adjusting means and tending to hold it against adjusting movement; and yieldable means interposed between said detent and the other member not carrying the adjusting means, for holding said detent means engaged with the adjusting means and urging said sections apart.

8. In combination, a shaft; a pair of opposed hub sections cooperating to form a bearing hub disposed substantially around said shaft, each section extending only about half way around the shaft; one pair only of the adjacent ends of said sections being free, the other pair being substantially hingedly connected; lever arms secured to the respective sections; yieldable means urging said sections apart; active and motive reciprocatory members pressing against said arms in a direction to force said sections to the shaft; means for adjusting one arm relative to the associated member; the hinge connection between said sections and the disposition of the sections and arms allowing movement of said sections and arms far enough from said shaft to permit complete lateral removal of the sections and arms entirely away from the shaft.

9. In combination, a shaft having an annular recessed seat therearound; a pair of opposed hub sections cooperating to form a bearing hub disposed substantially around said seat, each section extending less than half way around the shaft; one pair only of the adjacent ends of said sections being free, the other pair being substantially hingedly connected; lever arms secured to the respective sections; active and motive reciprocatory members pressing against said arms in a direction to force said sections toward each other and the shaft; and an adjusting means interposed between one of said arms and the associated member for adjusting such arm relative to the member and said sec tions relative to each other and the seat; said adjusting m ans being adjustable to allow movement of the sections from the seat, and the arms from opposition to said members, the hinge connection between said sections allowing movement of said sections and arms entirely away from the shaft.

1o. In combination, a shaft having an annurecessed seat therearound: a pair of opposed hub sections cooperating to form a bearing hub engaged in and disposed substantially around said seat, each section extending only about half way around the shaft; one pair only of the adjacent ends of said sections being free, the other pair being substantially hingedly connected to allow movement of the sections toward and from each other and the seat; lever arms secured to the respective sections and extending outwardly approximately radially from the shaft; active and motive reciprocatory members pressing against said arms respectively in directions to force said sections toward each other and to the shaft; and an adjusting means interposed between one arm and the associated member for adjusting such arm relative to the member and said sections relative to the seat and to allow relative movement of the arms from said members and the sections away from 5 the shaft and out of the seat, whereby the hubs may move end-wise of the shaft to move the arms from opposition to said members, whereby said sections may be moved further from the shaft; the hinge connection between said sections and the disposition of the sections and arms allowing movement of said sections and arms far enough from each other and the shaft to permit complete lateral removal of the sections and arms entirely away from the shaft. 11. In combination, a rocker shaft having an annular recessed seat therearound; a pair of opposed hub sections cooperating to form a bearing hub engaged in and disposed substantially around said seat to hold the hub against movement longitudinally of the shaft, each section extending only about half way around the shaft; one pair only of the adjacent ends of said sections being free, the other pair being substantially hingedly connected to allow movement of the sections toward and from each other and the seat; lever arms secured to the respective sections and the extending outwardly approximately radially from the shaft; active and motive reciprocatory members pressing against said arms respectively in directions to force said sections toward each other and to the shaft; and an adjusting means interposed between one arm and the associated member for adjusting such arm relative to the member and said sections relatively toward each other to hold the sections in the seat and adjusting said sections from each other sufficiently to allow relative'movement of the arms from said members and the sections away from the shaft and out of the seat, whereby 40 the hubs may move longitudinally of the shaft to move the arms from opposition to said members, said movement from opposition allowing said sections to be moved further from the shaft, and far enough from each other and the shaft to permit complete lateral removal of the sections and arms entirely away from the shaft; the hinge connection between said sections and the disposition of the sections and arms allowing said movement of said sections and arms. 12. A rocker arm for a shaft, said rocker arm comprising a pair of opposed members each including an arm and a hub section, each section being adapted to extend about opposite parts of the shaft; one pair only of the adjacent ends of said sections substantially hingedly connected; said lever arms being secured to the respective sections; a member between said sections; a hinge connection between said sections and said member the axes of the hinges being a considerable distance apart; adjusting means on one of the arms for engaging an actuating means and adjusting the distance of the arm from the actuating means; detent means engaging the adjusting means and tending to hold it against adjusting movement; and yieldable means interposed between said detent and the other member not carrying the adjusting means, for holding said detent means engaged with the adjusting means and urging said sections apart. 3.3. A rocker arm for a shaft, said rocker arm comprising a pair of opposed members each including an arm and a hub section, each section being adapted to extend about opposite parts of the shaft; one pair only of the adjacent ends of said sections substantially hingedly connected; said lever arm being secured to the respective sections; a member between said sections; a hinge connection between said sections and said member the axes of the hinges being a considerable distance apart; adjusting means on one of the arms for engaging an actuating means and adjusting the distance of the arm from the actuating means.

14. In combination, a rocker shaft having an annular recessed seat therearound; a pair of opposed huh sections cooperating to form a bearing hub engaged in and disposed substantially around said seat to hold the hub against movement longitudinally of the shaft, each section extending only about half way around the shaft; one pair only of the adjacent ends of said sections being free, a spring connecting the other pair and hingedly connecting the sections to allow movement of the sections toward and from each other and the seat; lever arms secured to the respective sections and extending outwardly approximately radially from the shaft; active and motive reciprocatory members pressing against said arms respectively in directions to force said sections toward each other and to the shaft; and an adjusting means interposed between one arm and the associated member for adjusting such arm relative to the member and. said sections relatively for movement toward and from each other; the spring hinge connection between said sections and the disposition of the sections and arms allowing said movement of said sections and arms.

WILBUR M. SWARTZELL. 

